Daily Archives: May 22, 2008

That Would Be the Rhodium Card

Posted on by

(Rhodium being a very expensive metal)

Nigerian phishing email

This is to officialy inform you that we have verified your CONTRACT/INHERITANCE payment of US$450,000,00and we the Senate committee on appropriation and finance have arranged your payment to be paid with an atm card in regard to an order from MR. President Alhaja Musa Yara’dua (GCFR) Federan Republic of Nigeria, an ATM card which you will use to withdraw your money from any ATM Machine in any part of the world have been approved for you. to receive your ATM card of $450,000,00 us dollars contact Mr.Famous Itsemhe on this email: [blah, blah, blah]

An ATM card to withdraw 450 thousand smackers? Yeah, right. I can fantasize (ubergeek fantasy, admittedly) that there’s a phishing database that measures the gullibility coefficient, and phishologists meticulously changing one variable at a time and measuring the response rates, with confidence intervals from their population sampling statistics. Because if it wasn’t for the ATM bit, I was ready to believe.

Besides, at $300 a day, it’ll take more than four years to get all the money. I want it now!

Still Better Than "A Burns for All Seasons"

Posted on by

More video that doesn’t have George C. Scott saying, “My Groin!” The Science Of Ball To Groin at glumbert. (Some annoying ads — and nothing else — tend to pop up on the video) This time, tennis balls (the projectile, not the target), while last time it was a baseball, but with a cup. Very different goals (though the same target), very different results.

via Uncertain Principles

Toys in the Office: Special Blasphemy Unit

Posted on by

It’s a hand-held catapult-like device to chuck things, and yes, those projectiles are small nun figurines. So, it’s a NUN-CHUCK, just like it says.

nunchuck.jpg

I don’t show this off to just anyone at the office; I wait until I know them and use my judgement. But this is the internet. Caveat emptor.

I really should round out my collection and become an equal-opportunity offender, so if anyone has a line on a protestant-o-pult, or an atheist arbalest (arbalatheist?) or even a Buddhistic ballista, let me know. I got the above at American Science & Surplus, though they’re also available at Archie McPhee (and perhaps elsewhere)

The Long and Winding Coil

Posted on by

One project over the last several weeks has been winding coils for the atomic fountains. There are two different requirements, one is the so-called “C-field” coils and the second is the MOT (magneto-optic trap) coil pair.

The “C-field” is the bias field in an atomic clock that essentially tells the atoms which way is up, i.e. it defines the quantization axis. It also shifts the frequency of the transition, so in a frequency standard you need to know what the field is. In a clock (there is a subtle difference) you care about the stability, i.e. you don’t want it to change, so it’s enough to feed this with a precision current source to give a bias field of a milligauss or so. Two layers, up and back, so the pitch on each layer should tend to cancel and leave you with a vertical field, and about 600 turns per layer. There are also extra shim windings at each end to better simulate an infinite solenoid — a real solenoid’s field drops off at the ends, so we boost it back up a little. The drift region, where the atoms oscillate between the two hyperfine states (the “tick” of an atomic clock), sees a very stable field.

Pretty easy, but time-consuming (as it were); the basic winding took more than four hours. What you see is the jig I used, which has a stepper motor and a home-built feed system that wets the wire with alcohol to activate the bonding material. Square wire is used so it doesn’t have any gaps.

Continue reading →